While we haven’t personally tested the feature, one owner of the earbuds says that users will have to choose between adjusting the volume or easy access to noise-cancellation. The implementation makes sense from a specific standpoint; like most earbuds, volume control requires both earbuds, with one side each either decreasing or increasing the volume level.
For owners of the Sony WF-1000XM3, installing the new firmware is pretty straightforward. You’ll need to open up the Sony Headphones Connect app and ensure that the earbuds are connected to your phone. Sony says that the update will take approximately 30 minutes to complete, both on iOS and Android OS. (Source: Sony, The Verge via Reddit)